books.google.com.au - There are many excellent books on quantum theory from which one can learn to compute energy levels, transition rates, cross sections, etc. The theoretical rules given in these books are routinely used by physicists to compute observable quantities. Their predictions can then be compared with experimental...https://books.google.com.au/books/about/Quantum_Theory_Concepts_and_Methods.html?id=pQXSBwAAQBAJ&utm_source=gb-gplus-shareQuantum Theory: Concepts and Methods